In this AFP file photo taken on July 19, 2016, Chris Collins delivers a speech on the second day of the Republican National Convention in Cleveland, Ohio.

Republican US lawmaker Christopher Collins, who was the first member of Congress to endorse Donald Trump for president, has been arrested on charges of insider trading.

Collins, 68, a member of the US House of Representatives representing New York state's 27th congressional district, surrendered to the FBI on Wednesday.

He was indicted on charges of insider trading, wire fraud, conspiracy and lying to the FBI. His son, Cameron Collins, and the father of his son’s fiancée, Stephen Zarsky, were also arrested on the same charges.

Collins, a staunch supporter of Trump, is up for re-election in November.

According to the indictment, Collins was allegedly involved to a scheme to gain insider information about Innate Immunotherapeutics Limited, a biotechnology company headquartered in Sydney, Australia.

The congressman was a member of Innate’s board of directors and held nearly 17 percent of the stock.

Federal prosecutors say the defendants tried to get early word on the results of trials of a drug the company developed to treat multiple sclerosis and were able avoid over $768,000 in losses by trading ahead of the public announcement of the failed drug trials.

Prosecutors allege that Collins passed along secrets to his son, Cameron, in June 2017. They say the son traded on the inside information and passed it to a third defendant, Stephen Zarsky. They say Zarsky traded on it and tipped off at least three others.

Collins has a track record of publicly backing Trump, including being one of the first sitting members of Congress to endorse his candidacy.

Most recently, Collins called for an end to US Special Counsel Robert Mueller’s investigation into alleged collusion between Trump’s election campaign and Russia.

He has blamed the administration of former President Barack Obama for failing to push back on Russia.

“I share President Trump’s continued frustration as the left continues to try to nullify the 2016 Presidential election with claims of Russian interference,” he said last year.